EP 2824442 A1 20150114 - Gas sensors and methods of controlling light sources therefore
Title (en)
Gas sensors and methods of controlling light sources therefore
Title (de)
Gassensoren und Verfahren zur Steuerung von Lichtquellen dafür
Title (fr)
Capteurs de gaz et procédés de commande de sources lumineuses pour ceux-ci
Publication
Application
Priority
- US 95832807 P 20070703
- US 89950807 A 20070906
- EP 08779916 A 20080701
Abstract (en)
A gas sensor, such as a photoacoustic gas sensor, includes a light source (5), a power source (80) in operative connection with the light source (20) and a control system (70) in operative connection with the light source (20) and the power source (80). The control system (70) is adapted to control power input from the power source (80) to the light source (20) such that the time period of the control frequency is shorter than the thermal time constant of at least one of (i) the infrared light source (20), (ii) the gas within the sensor, or (iii) a detector (40) of the sensor. The time period of the control frequency can, for example, be no greater than 1/3 of the thermal time constant, no greater than 1/10 of the thermal time constant, or even no greater than 1/20 of the thermal time constant. A feedback signal can be provided to the control system (70) assist in achieving control.
IPC 8 full level
G01N 21/17 (2006.01); H05B 44/00 (2022.01)
CPC (source: EP US)
G01N 21/1702 (2013.01 - EP US); G01N 2021/1704 (2013.01 - EP US); G01N 2201/12723 (2013.01 - EP US); G01N 2201/12792 (2013.01 - EP US)
Citation (applicant)
US 4740086 A 19880426 - OEHLER OSKAR [CH], et al
Citation (search report)
- [XY] EP 0584519 A1 19940302 - SIEMENS ELEMA AB [SE]
- [Y] US 4902958 A 19900220 - COOK II JAMES C [US]
- [Y] WO 9853646 A1 19981126 - SCHMIDT GREGORY W [US]
- [A] MENON V J, AGRAWAL D C: "Switching time of a 100 watt bulb", PHYSICS EDUCATION, vol. 34, no. 1, 1 January 1999 (1999-01-01), pages 34 - 36, XP007905934
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
DOCDB simple family (publication)
US 2009009769 A1 20090108; US 7835004 B2 20101116; AU 2008271056 A1 20090108; AU 2008271056 B2 20130307; BR PI0809804 A2 20141007; CA 2691376 A1 20090108; CN 101688830 A 20100331; CN 101688830 B 20130508; EP 2167939 A1 20100331; EP 2824442 A1 20150114; WO 2009005799 A1 20090108
DOCDB simple family (application)
US 89950807 A 20070906; AU 2008271056 A 20080701; BR PI0809804 A 20080701; CA 2691376 A 20080701; CN 200880022103 A 20080701; EP 08779916 A 20080701; EP 14185351 A 20080701; US 2008008183 W 20080701